The Six-Port Coupler: A New Approach to Measuring Voltage, Current, Power, Impedance, and Phase

A six-port coupler is described having four side arms whose outputs are proportional to the voltage, current, incident voltage wave, and reflected voltage wave at some desired measurement plane in the transmission line. The phase relationship between the outputs is the same as between corresponding quantities at the measurement plane. Complex impedance and phase angle as well as voltage, current, and power can be obtained from simple power or voltage magnitude measurements at the four side arms. A vector voltmeter used with this six-port becomes a direct reading vector impedance meter, admittance meter, or reflection coefficient meter.